1. Field of the Invention
The present invention relates to waste paper recycling processes and more particularly relates to a process for separating out portions of the waste paper which contain adhesive material and other contaminants from the remaining portions of the waste paper which are free from such contaminants. In addition, the invention relates to a new and improved adhesive used for binding books, magazines, catalogues, pamphlets and the like, wherein the adhesive aids in subsequent recycling processes because it facilitates separation of the portions of the paper having adhesive thereon from the portions that do not contain any such adhesive contaminants.
2. Description of the Prior Art
One major source of waste paper is books, magazines, catalogues, directories, pamphlets and the like, and many of these items are bound with an adhesive material which is used for binding the sheets together along an edge or back. Waste paper material which contains certain of these adhesive portions is difficult to use in recycling processes and many different methods have been tried for separating and eliminating the portions of the waste paper which contains the adhesive material from the remaining portions of the waste paper which are free of the adhesive used in the book binding process. Waste paper without adhesive material is readily suitable for recycling processes but, when certain adhesive or other contaminants are present, the waste paper is less valuable and more difficult to recycle.
One method that has been used to remove the adhesive material is to mechanically cut or shear the books, pamphlets and the like, along a line closely adjacent the bound edge or back so that only a small strip which contains the adhesive materials can be separated from the remaining portion of the paper sheets or pages which do not contain any adhesive material. This cutting and shearing is at best difficult and requires expensive cutting and handling apparatus to accomplish the necessary separation. Moreover, the books, magazines and other adhesively bound paper items have to be properly orientated when placed in the cutting or shearing apparatus so that excessive amounts of good waste paper material is not thrown away along with the contaminated material having the adhesive thereon. Methods have also been utilized in which it is attempted to chemically dissolve or otherwise assimilate the adhesive used in the binding process so that the contaminant effects are minimized. However, most of the adhesive materials that are widely used are of the hot melt type and very difficult to dissolve or remove chemically. Moreover, the cost of this approach is not economical when constrained by the present difference in price between waste paper that is free of adhesive type contaminant material and waste paper that contains a normal amount of such contaminating adhesive material.
It is therefor an object of the present invention to provide a new and improved method of separating unwanted or contaminated material from waste paper thereby to facilitate recycling of the non-contaminated waste paper remaining after separation.
Still another object of the present invention is to provide a new and improved method of separating adhesive containing portions of books, magazines and other bound paper items from the remaining portion of the paper sheets which are free of any adhesive binding materials.
Yet another object of the present invention is to provide a new and improved system of the character described wherein an adhesive material used in the book binding process is provided with a magnetic or paramagnetic component so that subsequently during a recycling process, the magnetic characteristics of the component may be used to facilitate separation of the portions of the waste paper having adhesive materials thereon from the remaining portions of the waste paper which are free of such adhesive contaminants.
Another object of the present invention is to provide a new and improved adhesive material especially adapted for use in binding books, papers, magazines and the like wherein a magnetic component is included in the adhesive used in the binding process and which component is useful in subsequent recycling processes in accordance with the invention for aiding in separating the portions of the waste paper that have adhesive thereon from the remaining waste paper which is relatively free of adhesive materials.
Yet another object of the present invention is to provide a new and improved method of separating unwanted material from waste paper in books, pamphlets and the like wherein mechanical cutting or shearing of the bound edge portion or back is not required.
Yet another object of the present invention is to provide a new and improved system of recycling waste paper wherein during a book binding type process, an adhesive material with a magnetic component herein is utilized so that subsequently during a recycling process, the magnetic characteristics of the adhesive are available for use in magnetic separation of the portions of the books having adhesive thereon from the remaining portions of the waste paper which is not contaminated with adhesive substance.
Two common means for separating magnetic from non-magnetic materials are provided including a permanent magnet or a magnetic field due to a permanent magnet on one hand or a magnetic field developed by an electromagnet, and this latter type can be a high gradient field or a field of relatively lower magnetic strength.
Yet another object of the present invention is to provide a new and improved method of the character described wherein waste paper material is pulped and mixed with water to form a slurry as is standard in the recycling of waste paper which slurry is then passed through a high intensity or high gradient magnetic separator for separating the waste paper having adhesive thereon from the portions of waste paper which is free of adhesives or is uncontaminated.
Still another object of the present invention is to provide a new and improved method of recycling waste paper material using a high intensity magnetic separation process for eliminating unwanted or contaminated portions from the waste paper that is treated.